Bone rig doesn't work?
Use weight paint mode in order to fix the geometry effected by the bones.

Select the mesh and you can change to weight paint mode by pressing CTRL + TAB.

Use CTRL + Right Click to select bones. You will see colors ranging from Red (a weight of 1) to Blue (a weight of 0). A weight of 1 means the geometry moves with the bone and a weight of 0 means the geometry is not affected by the bone. You can use the subtract brush to remove weight from geometry you do not want the bone to affect.

You can learn more about weight paint mode here: http://blender-manual-i18n.readthedocs.io/ja/latest/modeling/meshes/vertex_groups/weight_paint.html